Immune regulation by intralymphatic immunotherapy with modular allergen translocation MAT vaccine.

BACKGROUND: Allergen-specific immunotherapy (SIT) faces problems related to side effects and limited efficacy. Direct administration of allergen extracts into lymph nodes induces increased specific IgG production and T-cell responses using significantly lower allergen doses. METHODS: In this study, mechanisms of immune regulation by MAT vaccines in vitro and in allergen-SIT of cat-allergic rhinitis patients, who received 3 inguinal intra-lymph node injections of MAT-Fel d 1 vaccine, were investigated in PBMC and cell cultures for specific T-cell proliferation, Fel d 1-tetramer-specific responses, and multiple immune regulatory molecules. RESULTS: MAT-Fel d 1 vaccine was efficiently internalized by antigen-presenting cells. This was followed by precaspase 1 cleavage to caspase 1 and secretion of IL-1ß, indicating inflammasome activation. Mat-Fel d 1 induced specific T-cell proliferation and an IL-10- and IFN-γ-dominated T-cell responses with decreased Th2 cytokines at 100 times lower doses than Fel d 1. Induction of immune tolerance by MAT-Fel d 1-ILIT involved multiple mechanisms of immune suppression. Early Fel d 1-specific T-cell activation was followed by full T-cell unresponsiveness to allergen after 1 year in the MAT-Fel d 1 group, characterized by increased allergen-specific T regulatory cells, decreased circulating Fel d 1 tetramer-positive cells, increased IL-10 and FOXP3 expression, and change in the HR2/HR1 ratio toward HR2. CONCLUSIONS: This study demonstrates the induction of allergen tolerance after 3 intra-lymph node injections of MAT-Fel d 1 vaccine, mediated by increased cellular internalization of the allergen, activation of inflammasome, and generation of allergen-specific peripheral T-cell tolerance.

Regulation and expression of IL-32 in chronic rhinosinusitis.

BACKGROUND: Activated T lymphocytes and their interaction with resident tissue cells, particularly epithelium, play important roles in inflammatory processes in chronic rhinosinusitis (CRS). IL-32 is a recently described cytokine, which is expressed in a variety of tissue cells and involved in the pathogenesis of several chronic inflammatory diseases. METHODS: Human sinus epithelial cells were isolated from biopsies and stimulated with different cytokines, which play a role in the pathogenesis of CRS. IL-32 mRNA expression was analyzed using real-time-PCR, IL-32 protein was determined by Western blot and flow cytometry as well as immunofluorescent staining in primary sinus epithelial cells and nasal biopsies from patients with CRS and healthy controls. RESULTS: IL-32 mRNA was upregulated by TNF-α and IFN-γ in primary sinus epithelial cells, whereas IL-1 ß, IL-4, IL-13, and IL-17 did not influence IL-32 expression. IL-32 mRNA expression was significantly higher in human primary sinonasal epithelial cells (HSECs) cocultured with Th1 cells compared with HSECs cocultured with Th0 or Th2 cells. IL-32 mRNA expression was significantly higher in biopsies from sinus epithelial tissue of CRS patients with nasal polyps compared with healthy subjects (P = 0.01). IL-32 was detected in biopsies from patients with CRS, whereas it was scarcely present in control tissues. CONCLUSION: The induction of IL-32 by TNF-α, IFN-γ and Th1 cells as well as its increased expression in sinus tissues from CRS patients with nasal polyps demonstrated a potential role for IL-32 in the pathogenesis of CRS.